The invention relates to a locking tongue for a seat belt comprising an inserting portion adapted to be inserted in a belt buckle and a deflecting portion for webbing, wherein the deflecting portion includes a webbing passage as well as a clamping element for the webbing and the clamping element is movable between a home position in which the webbing is freely movable and a blocking position in which the clamping element is moved against a wall of the webbing passage so that the webbing is clamped between the clamping element and the wall of the webbing passage, and wherein at least one spring element is provided for acting upon the clamping element in the home position.
In three-point seat belts locking tongues form a deflecting point between a first section of the seat belt which in the case of restraint restrains the pelvis of the vehicle occupant and a second section which protects the upper body part of the vehicle occupant from a forward out-of-position movement. The locking tongue is threaded onto the webbing of the seat belt with the deflecting section so that the locking tongue can be freely displaced on the webbing. In this way, when fastening the seat belt, the length of the two sections of the seat belt can be adapted to the vehicle occupant. In addition, by displacing the webbing through the locking tongue the webbing can be oriented so that the latter is evenly adjacent to the vehicle occupant.
In the case of restraint, the upper body part may happen to move forward when the seat belt is blocked. Since the webbing is movably guided in the locking tongue, the webbing can be displaced so that the section contacting the upper body part is extended and the section contacting the pelvis is shortened, which may cause the seat belt to constrict the pelvis region. In order to prevent this, locking tongues include clamping elements which in the case of blocking of the seat belt may be displaced between a home position in which the webbing is freely movable and a blocking position in which the clamping element clamps the webbing to the locking tongue so that no webbing displacement is possible between the first and second sections of the seat belt. In this way, the pelvis region is protected against constriction by the seat belt and the upper body part is protected against excessive forward out-of-position movement.
In order to return the clamping element to the home position after completion of the case of restraint, spring elements are provided for acting upon the clamping element in the home position. Usually, for this purpose spiral springs or leaf springs are employed. Such locking tongue is known, for example, from DE 20 2010 013 986 U1. Said spring elements in addition have the function to maintain the clamping element in the borne position free from play so that any noise by rattling of the clamping element is prevented or at least reduced. For this purpose, it is required, however, to mount the spring elements to the locking tongue while they are biased. The large number of individual parts and the mounting of the spring elements under bias render the assembly of the locking tongues very complicated.